Sampling devices have been used extensively to identify microbes and other bioagents for various applications including protection of military and civilian population against enemy attacks. Such sampling devices are typically designed to selectively sample either air or surfaces. Aerosol samplers include pre-collectors and a number of concentration stages for isolating the particle sizes of interest. Thus, these aerosol sampling devices are heavy and require high power for operation. Surface sampling devices contain components for managing liquids, and are thus difficult to operate in a dynamic environment and not readily portable. In addition, surface sampling devices are typically incapable of separating the sample particles by size, resulting in samples containing undesirable larger size particles which undesirably interfere with analysis of any bioagents in the sample. These sampling devices are not readily portable, not suited for large area sampling, and require alternating current power sources.
Other sampling devices selected from Q-tips, sponges and swabs to sample surfaces visibly tainted with powder are available. However, methods using such devices are only suitable for non-porous surfaces and small area sampling, thus they are tedious, time consuming and labor intensive to implement.
Accordingly, there is a need in the art to develop an external filter assembly designed to convert a suction cleaning device such as a portable, hand-holdable vacuum cleaner into a sampling device, thus enabling large numbers of sampling devices to be rapidly constructed using commercially available components in short time and at relatively modest cost. There is a further need for an external filter assembly adapted for modifying a suction cleaning device to perform biological sampling in a manner to enhance portability and sampling area size, and reduce cost, while producing a testable quantity of aerosol and/or surface-based particles for subsequent testing and analysis.